The endpoints of a diameter of circle $M$ are $(-1,-4)$ and $(-7,6)$. What are the coordinates of the center of circle $M$? Express your answer as an ordered pair.
Answer: The midpoint of a diameter of a circle is its center. Thus, $M$ is the midpoint of the segment from $(-1,-4)$ to $(-7,6),$ so $M$ has coordinates \[\left(\frac{-1+(-7)}{2},\frac{-4+6}{2} \right)=\boxed{(-4,1)}.\]